Unusual valences in rare-earth halides

Journal Article · · Chemistry of Materials; (United States)

DOI:https://doi.org/10.1021/cm00024a012· OSTI ID:7072774

Meyer, G; Meyer, H J ^[1]

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1. Universitaet Hannover (Germany)

The valence of an atom in a particular compound is considered unusual when there is a difference between the localized valence and the oxidation number. The degrees of delocalization of electrons may be different. Total delocalization gives rise to a conduction band. There may also be partial delocalization with multicenter or cluster bonding. With such a definition, reduced rare-earth halides such as metallic LaI[sub 2] or semiconducting Pr[sub 2]Br[sub 5] and Gd[sub 2]Cl[sub 3] with [Gd[sub 6]] clusters contain unusual valences but TmI[sub 2] does not. In addition to the generalities of the synthesis and properties of reduced rare-earth halides, the electronic structures have been calculated making use of the extended Hueckel algorithm. These calculations aim to yield a better understanding of bonding and the conductivity properties of these compounds. 55 refs., 20 figs.

• OSTI ID: 7072774
• Journal Information: Chemistry of Materials; (United States), Journal Name: Chemistry of Materials; (United States) Vol. 4:6; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
664100 -- Theory of Electronic Structure of Atoms & Molecules-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ALGORITHMS
BROMIDES
BROMINE COMPOUNDS
CHEMICAL BONDS
CHLORIDES
CHLORINE COMPOUNDS
ELECTRONIC STRUCTURE
GADOLINIUM CHLORIDES
GADOLINIUM COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
MATHEMATICAL LOGIC
PRASEODYMIUM BROMIDES
PRASEODYMIUM COMPOUNDS
RARE EARTH COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
VALENCE
YTTRIUM CHLORIDES
YTTRIUM COMPOUNDS